Implants

ABSTRACT

An implant assembly includes a first implant member, a second implant member, and a contractible element that is connected between the first and second implant members. The first implant member is configured to be placed against a first bone portion, and the second implant member is configured to be placed against a second bone portion. The contractible element is fixed at a first end to one of the first and second implant members, and movable at a second end with respect to one of the first and second implant members so as to induce tension in the suture, thereby providing a compressive force against the first and second bone portions. The second end can then be fixed with respect to the first and second implant members. The contractible element can contract in length in response to bodily fluids, thereby ensuring adequate post-operative compression. An instrument is also disclosed that is configured to implant the first and second implant members adjacent the first and second bone portions, respectively.

FIELD OF DISCLOSURE

The present disclosure relates to implants, instruments, methods ofimplantation and methods of manufacture.

BACKGROUND

Implants for holding together portions of a bone to support bone healingare known. For instance, FIG. 11 shows an example of a conventionalimplant. The implant, commercially available from DePuy Synthes®, havinga place of business in West Chester, Pa., is used to hold togetherfractured portions of a sacrum. The implant can include one or more rodassemblies 200, each having a rod 201 that extends through first andsecond opposed portions 12 and 11 of the ilium, respectively, that arepositioned on opposed medial-lateral sides of the sacrum S. The rod canbe threaded, and configured to threadedly receive respective first andsecond nuts 202 and 204 at its opposed first and second ends. The firstand second nuts 202 and 204 can be threaded onto the rod 201, andcompressed against the first and second portions 12 and 11 of the iliumso as to provide a compressive force to a fractured sacrum S. Theimplant can further include a first washer 206 disposed between thefirst nut 202 and the first portion 12 of the ilium, and a second washer208 disposed between the second nut 204 and the second portion 11 of theilium.

FIG. 12 shows another conventional implant that uses compression to holdbone portions together during a healing process. The implant illustratedin FIG. 12 is used for syndesmosis fixation, and is commerciallyavailable under the product name TightRope® from Arthrex, Inc., having aplace of business in Napes, Fla. The implant illustrated in FIG. 12includes a bone plate 210 and a button 212 that are disposed on oppositesides of bone. The bone plate 210 is anchored to the bone using one ormore screws 214, and a suture 216 is drawn through the bone from thebutton 212 to the bone plate 212 and fastened to the bone plate 212 toprovide compression to the bone.

Yet another conventional implant shown in FIG. 13 uses compression tosupport a healing process of the acromioclavicular (AC) joint. Theimplant illustrated in FIG. 13 is the MINAR® system, commerciallyavailable from Karl Storz GmbH & Co. KG, having a place of business inBerlin, Germany. The implant of FIG. 13 can include first and secondbuttons 218 and 220 that are disposed on opposed surfaces of theclavicle 217 and the coracoid process 219, respectively, and a suture221 that extends through the first button 218, through the AC joint andwraps around the second button through first and second apertures,respectively, and is drawn again through the AC joint and through thefirst button 218. The suture 221 can be fastened to the first buttonsuch that the suture 221 provides compression between the first andsecond buttons 218 and 220, and thus provides compression between theclavicle and the coracoid process.

A problem common to all these systems is that once implanted and withoutadditional surgery it is complicated to adjust the implant to, forexample, maintain the compressive force supporting the healing process.

SUMMARY

In a first aspect, an implant assembly has a first implant member, asecond implant member and a contractible element. The contractibleelement spans between the first implant member and the second implantmember. The contractible element has a first end fixed to one of thefirst and second implant members and a second end adjustably fixable toa fixing arrangement provided on one of the first or second implantmembers.

The fixing arrangement may be provided on the implant member to whichthe first end of the contractible element is fixed.

The second end of the contractible element may be fixed to the firstimplant and adjustably fixable to the fixing arrangement that is locatedon the first implant member.

The fixing arrangement may have an adjustment region in which thecontractible element is adjustable relative to the implant member.

The fixing arrangement may comprise a fixing region in which the secondend of the contractible element is fixable with one or more of a knot, acrimp, a cam-lock, a set screw or a clamp

The contractible element may be capable of self-contracting. Thecontractible element may be thread-like and have a core surrounded by amesh. The contractible element may have a first length measured from thefirst end to the second end. The swelling of the core may cause the meshto expand causing the contractible element to contract from the firstdistance to a second shorter distance. The swelling of the core mayoccur due to exposure of the core to bodily fluids.

The fixing arrangement may have an adjustment region. The adjustmentregion may have a channel defined in the implant member through whichthe second end of the contractible element may be passed.

The contractible element may be thread-like. At least one pulley may bearranged in one of the first or second implant members. The thread-likecontractible element may be looped from the first end fixed in the firstimplant member to the adjustably fixable second end arranged in one ofthe first or second implant members through at least one pulley locatedin one of the first and second implant members. In particular, the firstend of the thread-like contractible element may be fixed in the firstregion to the first implant member, looped between a plurality ofpulleys arranged in the first and second implant members and adjustablyfixable to the fixing arrangement provided on the first member.

The implant member with the pulley may have a first channel and a secondchannel. The or each channel may define a first opening on a firstsurface of the implant member and a second opening on a second surfaceof the implant member. The pulley may be defined by a smooth transitionbetween the first openings and/or the second openings.

In a second aspect of the present invention there is provided an implantassembly. The implant assembly may have a first holder and a secondholder for holding a suture in a fixed position relative to the implantmember. The first holder may be arranged to fixedly hold the suture. Thesecond holder may be arranged to adjustably hold the suture.

In a third aspect of the present invention there is provided an implantassembly. The implant assembly may have a plurality of pulleys. Thepulleys may be arranged to receive and hold a suture.

In a fourth aspect of the present invention there is provided a sutureholding mechanism. The suture holding mechanism may have a lockingelement deployable between an open configuration in which a suture maymove relative to the suture holding mechanism and a closed configurationin which the suture is immovable relative to the suture holdingmechanism.

The suture holding mechanism may have a first channel in which a suturemay be arrangeable. The locking element may be moveable in a directionwhich is transverse to a channel axis of the first channel between theopen and closed configurations. In the open configuration, the suturemay be moveable relative to the first channel. In the closedconfiguration, the suture may be immovable relative to the firstchannel. In the closed configuration, when compared with the openconfiguration more of a leading end of the locking element may belocated in the first channel. In use with a suture positioned in thefirst channel, a closed configuration occurs when the amount of theleading end located in the channel restricts movement of the suturerelative to the first channel. In this configuration, the leading endpresses the suture against a wall forming the first channel to hold thesuture in position relative to the first channel. In a completelyextended position, the locking element may extend across the firstchannel and the leading end may abut the wall defining the firstchannel.

The suture holding mechanism may have a deployment mechanism arranged todeploy the locking element between the open and closed configurations.The deployment mechanism may have a moveable element engageable with thelocking element. Movement of the moveable element in a first directionmay engage a first end of the moveable element with a trailing end ofthe locking element to deploy the leading end into the first channel.The moveable element may be a set screw. The set screw may have atapered end and the trailing end may be angled to correspond to theangle forming the tapered end.

In a fifth aspect of the present invention there is provided aninstrument for inserting an implant assembly of the first aspect. Theinstrument has a body having a chamber for housing the implant assembly,an opening into the chamber and an external surface shaped anddimensioned to be passed through boreholes formed in a bone. Theinstrument has a deployment element moveable between a first positionand a second position relative to the chamber. The deployment elementhaving an implant engaging member. When an implant assembly is housed inthe chamber, movement of the deployment element from the first positionto the second position engages the implant engaging member with theimplant assembly to move at least part of the implant assembly out ofthe chamber through the opening.

An external surface of the instrument may have drilling flutes formaking boreholes in a bone.

In a sixth aspect of the present invention there is provided a method oftreating a musculoskeletal condition. The method may comprises one ormore steps, which may involve:

selecting an implant assembly having a first member, a second member anda self-contracting element connecting the first member to the secondmember;

implanting the implant assembly in an arrangement, the arrangementselected to treat the musculoskeletal condition;

tensioning the self-contracting element to set an initial compressionthat the first and second members apply to a location to treat themusculoskeletal condition, the location being a location of themusculoskeletal condition; and

maintaining a compression post-operatively during the treatment of themusculoskeletal condition;

The compression may be maintained post-operatively through interactionof the self-contractible element with bodily fluids that activate a selfcontracting feature of the self contracting element. The initialcompression may be a compression determined as being necessary fortreating the musculoskeletal condition. The compression maintainedpost-operatively may be substantially the same as the initialcompression. The treatment of musculoskeletal condition may involvetreating, for example, of a bone fracture, a torn or ruptured ligament,and a torn AC-CC Joint.

A tension applied to the self-contracting element may cause thecompression that the first and second members apply to the location. Thetensioning step may involve:

identifying when a tension applied to the self-contracting element maycause the initial compression; and

setting the initial compression by fixing the self-contracting elementto the first implant.

The tensioning step may involve checking a tension applied to theself-contracting element with a tension measurer.

The step of implanting may include arranging the implant assembly in thearrangement by:

positioning the second implant at a respective position adjacent thelocation;

positioning the first implant at a respective position adjacent thelocation, the respective position corresponding to the first implantbeing different than the respective position corresponding to the secondimplant, and selected so that the initial compression applied to thelocation by the first and second implants is appropriate for thetreatment of the musculoskeletal condition.

The step of implanting may include the step of positioning an instrumentcontaining the implant assembly adjacent the location and manipulatingthe instrument to arrange the implant assembly in the arrangement.

The step of positioning an instrument may involve positioning theinstrument through one or more holes formed in musculoskeletal tissue,preferably, through holes formed in a bone portion or a plurality ofbone portions. The holes may be formed by drilling through themusculoskeletal tissue. The instrument may have a container for holdingthe implant assembly. The step of positioning the instrument may involvepositioning the container adjacent the location.

The instrument may have a deployer arranged to position the first andsecond members of the implant assembly. The step of manipulating theinstrument may involve:

moving the deployer to position the second implant at a first positionadjacent the location; and

moving the deployer to position the first implant at a respectiveposition adjacent the location, the respective position of the firstimplant being different than the respective position of the firstimplant, and selected so that the initial compression applied to thelocation by the first and second implants is appropriate for thetreatment of the musculoskeletal condition.

The instrument may have a container for holding the implant assembly.The step of manipulating may involve deploying the first and secondimplants out from the container. The container may have a first openingand a second opening and the step of manipulating may involve the stepof deploying the first implant through the first opening and the secondimplant through the second opening. The instrument may have a deployerarranged to position the first and second members of the implantassembly and the first and second openings may be connected by achannel. The step of manipulating may involve translating the deployeralong the channel in a first direction to position the first implant ata first position adjacent the location through the first opening. Thestep of manipulating may involve translating the deployer along thechannel in a second direction to position the second implant at a secondposition adjacent the location through the second opening.

The method may further include the step of removing the instrument afterthe implant assembly is implanted in the arrangement.

In a seventh aspect of the present invention there is provided a methodof manufacturing an implant assembly. The method may involve the step oftaking a first implant member and a second implant member, andconnecting a self-contracting element to the first and second implantmembers.

The self-contracting element may be a thread-like element, and each oneof the first and second implant members may have a pulley arrangement.The connecting step may involve threading the thread-likeself-contracting element through the pulley arrangement. The firstimplant member may have a first holder for holding a first end of thethread-like self-contracting element. The implant member may have asecond holder for holding a second opposed end of the thread-likeself-contracting element. The thread-like self-contracting element maybe adjustably held by the second holder.

In an eight aspect of the present invention there is provided a methodof deploying an implant assembly from an instrument and may involve thesteps of:

-   -   selecting an instrument containing the implant assembly, the        instrument having a channel and a deployment element moveable        between a first position and a second position relative to the        channel;    -   moving the deployment element from the first position to the        second position during which the deployment element engages with        the implant assembly and pushes the implant assembly out of the        channel.

The moving step may involve pushing a portion of the implant assemblyout of the channel.

The implant assembly may have a first member and a second member. Thestep of moving the deployment element may involve engaging thedeployment element with the second member and pushing the second memberout of the channel through an exit point as the deployment element ismoved from the first position to the second position. The first membermay remain in the channel whilst the second member is being pushed outof the channel.

The implant assembly may have a first member deployable separately fromthe second member. The step of moving the deployment element may involvethe deployment element engaging with the second member and pushing thesecond member out of the channel through an exit point as the deploymentelement is moved from the first position to the second position. Thefirst member may remain in the channel whilst the second member is beingpushed out of the channel.

The implant assembly may have a first member and a second memberremovable separately from the channel through an exit point of thechannel. The exit point through which the first and second members maybe removed from the channel may be the same exit point.

The implant assembly may have a first member and a second memberremovable separately from the channel. The method may further involveremoving the first member from the channel by drawing the instrumentover the first member. The instrument may be drawn over the first memberafter the deployment element has been moved to the second position. Theinstrument may be drawn over the first member after the second memberhas been pushed out of the channel.

The implant assembly may have a first member and a second member. Themethod may further involve the step of:

-   -   arranging a portion of the instrument at a deployment site        before the moving step;    -   the moving step may involve deploying the implant assembly at        the deployment site; and    -   withdrawing the instrument from the deployment site after the        moving step.

The implant assembly may have a first member and a second member. Themethod may further involve the step of:

-   -   arranging a portion of the instrument at a first deployment site        before the moving step;    -   moving the deployment element from the first position to the        second position to deploy the second member at the first        deployment site; and    -   drawing the instrument over the first member to deploy the first        member at a second deployment site, which is preferably        different to the first deployment site.

The method may further involve a step of positioning the instrumentthrough at least one hole in musculoskeletal tissue before the movingstep. The at least one hole may be bore hole through a bone portion. Theat least one hole may include a first and a second hole, the first holemay be a hole through a first bone portion and the second hole may be ahole through a second bone portion. The first hole may be located in anIlium crest situated on one side of the sacrum and a second hole may belocated in an Ilium crest situated on the other side of the sacrum.

The implant assembly may have a self-contracting element connecting afirst member to a second member. The self-contracting element may have afluid activatable feature which acts against the tendency to bestretched.

In a ninth aspect of the present invention there may be provided amethod of fixing a thread like element to an implant. The method mayinvolve:

-   -   pulling the thread-like element through a channel in the implant        assembly, the implant assembly having a holder; and    -   fixing the thread-like element to the holder thereby preventing        movement of the thread-like element relative to the channel.

In a tenth aspect of the present invention there may be provided amethod of maintaining compression between a first implant member and asecond implant member, the method involve the steps of:

-   -   selecting a first implant member and a second implant member        that are connected to each other by a self-contracting element;    -   arranging the first implant member to abut a first surface and        the second implant member to abut a second surface;    -   tensioning the self-contracting element to set an initial        compression applied to the first and second surfaces by the        first and second implants;    -   maintaining a post-setting compression through interaction of        the self-contracting element with fluids that activate a self        contracting feature of the self contracting element.

The post setting compression may be substantially the same as theinitial compression.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the present disclosure will now be describedbelow with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an implant assembly including first andsecond plates, and a contractible element joined to the first and secondplates, in accordance with one embodiment;

FIG. 2A is a schematic view of the implant assembly illustrated in FIG.1 implanted on first and second portions of an Ilium;

FIG. 2B is another schematic view of the first plate of the implantassembly of FIG. 1, shown implanted on first portion of the Ilium;

FIG. 2C is another schematic view of the second plate of the implantassembly of FIG. 1, shown implanted on second portion of the Ilium;

FIG. 3 is a schematic view of first and second implants of the typeillustrated in FIG. 1, shown implanted on first and second portions ofan Ilium;

FIG. 4 shows a perspective view of the first plate of the implantassembly shown in FIG. 1;

FIG. 5A is a sectional view of a holder of the first plate of FIG. 4,shown in an open configuration;

FIG. 5B is a sectional view of the holder of the first plate of FIG. 4,shown in a closed configuration;

FIG. 6A is a partial sectional side view of the first plate of FIG. 4,taken along line A-A;

FIG. 6B is a partial sectional side view of the first plate asillustrated in FIG. 6A, but constructed in accordance with analternative embodiment;

FIG. 7 is a perspective view of the second plate of the implant assemblyof FIG. 1;

FIG. 8A is a perspective view of a frame of alternative embodiments ofthe second plate of FIG. 1;

FIG. 8B is a perspective view of a first alternative embodiment of thesecond plate of FIG. 1, including the frame shown in FIG. 8A;

FIG. 8C is a perspective view of a second alternative embodiment of thesecond plate of FIG. 1, including the frame shown in FIG. 8A;

FIG. 8D is a perspective view of a third alternative embodiment of thesecond plate of FIG. 1, including the frame shown in FIG. 8A;

FIG. 8E is a perspective view of a fourth alternative embodiment of thesecond plate of FIG. 1, including the frame shown in FIG. 8A;

FIG. 9A is a perspective view of a shaft of the second plate constructedin accordance with the embodiments shown in FIGS. 8B to 8E;

FIG. 9B shows a perspective view of a pulley of the second plateconstructed in accordance with the embodiments shown in FIGS. 8C to 8E;

FIG. 10A is a perspective view of an instrument configured to insert theimplant assembly of FIG. 1;

FIG. 10B is an enlarged perspective view of a first end of theinstrument of FIG. 10A;

FIG. 10C is an enlarged perspective view of a second end of theinstrument of FIG. 10A;

FIG. 10D is a front elevation view of the first end of the instrumentshown in FIG. 10A;

FIG. 11 shows an example of a prior art implant;

FIG. 12 shows another example of a prior art implant; and

FIG. 13 shows yet another example of a prior art implant.

DETAILED DESCRIPTION

Referring to FIGS. 1 to 10D generally, an implantation systemconstructed in accordance with one embodiment includes one or moreimplant assemblies 1 and an instrument 50 configured to implant theimplant assemblies 1 into a patient's body. The implant assemblies 1 caneach include a first implant member, which could be in the form of afirst plate 10, a second implant member, which could be in the form of asecond plate 30, and a contractible element 5 that is linked to thefirst and second plates 10 and 30, respectively. In use, the first plate10 may be deployed relative to a first portion of musculoskeletaltissues, for example a first bone portion 12, and the second plate 30may be deployed relative to a second portion of musculoskeletal tissues,for example a second bone portion 11. The first bone portion 12, forinstance, can be the ilium bone of the right hip, and the second boneportion 11 can be the ilium bone of the left hip.

The first and second bone portions 12 and 11, respectively, can beopposed first and second portions of an ilium that are separated by asacrum S, and thus opposed on opposite sides of the sacrum S. Thecontractible element 5 may then be adjusted so that the first plate 10and second plate 30 are arranged to abut and apply a compressive forceto the respective first and second bone portions 12 and 11,respectively. The contractible element 5 is configured to interact withbodily fluids after implantation, such that the contractible element 5self-contracts after implantation so as to maintain the compressiveforce as will be described in more detail below.

Referring to FIGS. 2A to 2C a particular use of the implant assembly 1is shown from a posterior view of the sacrum and Ilium. The implantassembly 1 is positioned to apply a compressive force to the Ilium onthe right and left side of the sacrum. In particular, the first plate 10is positioned on the lateral surface 12 a of the first bone portion 12,which can be the ilium bone on the right hip, as described above. Thesecond plate 30 is positioned on the lateral surface 11 a of the secondbone portion 11, which can be the Ilium bone on the left hip asdescribed above. The first and second plates 10 and 30 are configured toapply compression to the lateral surfaces 12 a and 11 a so as tomaintain compressive pressure on the sacrum bone S that is disposedbetween the first and second bone portions 12 and 11 of the Ilium. Whenthe sacrum S is fractured, the compression is used to promote bonehealing. Since the implant assembly 1 has the ability to maintain thecompressive force throughout bone healing, the reduction of the fractureis maintained and bone healing promoted. That is, the maintenance of thecompressive force may counteract or resist a tendency of the first plate10 and second plate 30 to creep away from each other due to the variousfactors, such as, bodily fluids, soft tissue movement, stretching oftraditional sutures and bone movement that may act upon the implantwhilst implanted in situ. As illustrated in FIG. 3, the implantationsystem can include first and second implant assemblies 1 a and 1 b,which can each be constructed as described herein with respect to theimplant assembly 1, and can be positioned at different locationsrelative to an Ilium crest to apply a compressive force to the sacrum S.

The implant assembly 1 has a suture, or other suitable thread-likeelement, as the contractible element 5. The suture 7 has a first fixedend 5 a and a second tensioning free end 5 b and is elongate along alongitudinal axis. The suture 7 is capable of self contracting to reducea distance between the fixed end 5 a and the free end 5 b with respectto the longitudinal axis. Such a suture 7 is disclosed is U.S. PatentPublication No. 2008/0281355, the disclosure of which is expresslyincorporated herein in its entirety by reference. In particular, thesuture 7 has a core surrounded by a mesh of, for example, threadsarranged helically around the core, in particular braided or interlacingthreads, such as textile threads typically used for monofilament ormultifilament suture materials. In particular, threads of known suturematerials, such as those typically used in surgical suture materials,may be used. For example, the threads may be stretched polyesters,polyamides, polyolefins, polyaramides, expanded or densely halogenatedpolymers or high-strength ladder polymers such as polyetherether ketone,captones, polyurethanes, PUR, siloxane, PEG or other permeable, inparticular semi permeable products in the form of osmotic, elastic orplastic and geometrically extendible membranes (e.g. stretching of axialfolds, pleats or undulations).

Referring now to FIG. 1, the contractible element 5 can be configured asa suture 7 that can have a rest state in which it is inactive, i.e., astate when it is not self-contracting. The suture 7 can be elongatealong a longitudinal direction between the first and second plates 10and 30, and can include a core and a mesh that surrounds the core. Themesh can define threads such that, when the suture 7 is in the reststate, the threads of the mesh surrounding the core can be interwovenand angularly offset with respect to the longitudinal direction of thesuture 7. For instance, the threads of the suture can be oriented, forexample, at an angle of between 5 and 50 degrees, for example 30degrees, with respect to the longitudinal direction of the suture 7. Thecore 41 is a material swellable from a first thickness to a greatersecond thickness to transition the threads to a contracted state. Theswelling of the core results in the angle of the threads of the meshincreasing with respect to the longitudinal direction and with respectto the angle at which they are orientated in the rest state. Forexample, if in the rest state the threads were angled at 30 degrees inthe contracted state the threads could be at an angle greater than 30degrees for, for example, at angle between 35 to 50 degrees, forexample, 45, 46, 47 and 48 degrees. In the contracted state, thedistance between opposed sides of the mesh has increased, which resultsin a contraction of the suture in the longitudinal direction.

The swelling of the core can be caused by one or both of chemical andphysical processes. The swelling process can be achieved, for example,by the core being osmotic. That is, the core can have an osmoticallyactive substance (for example salt, particulate form of a water-solublesubstance (for example saccharides) or highly concentrated solution ofthese substances in an elastic tube), which accordingly is configured toreceives and retain (for instance absorb or adsorb) water. Theosmotically active substances may also include biocompatible inorganicsalts and aqueous solutions thereof, for example sodium chloride (NaCl)or calcium chloride, calcium carbonate, tricalcium phosphate, ororganic, osmotically active molecules can be used, for examplelow-molecular-weight polysaccharides such as dextran. In a particularexample, the core may have a filamentary polymer material, for example athermoplastic elastomer (polyurethane, polyester), a crosslinkedelastomer (silicone, polyurethane, elastin, collagen) or a gel(polyethylene glycol, alginate, chitosan) in which salt crystals areincorporated. To improve handling and to further influence the kineticsof osmosis, the osmotically active substances can also be embedded in abiocompatible gel or hydrogel (for example from the group of alginates,chitosans or copolymers thereof, polyacrylates, polyethylene glycol,etc.) or, as explained above, in an elastomer. In addition, the core maybe made up of several membrane-like layers or can also be provided withstable or soluble diffusion-inhibiting layers. If hydrogels are used,such a membrane-like property can also be achieved by means of acrosslinking density that increases considerably toward the outside. Theconcentration differences effecting osmosis are to be achieved betweenthread core and surrounding blood or interstitial and/or intrastitialfluid of the patient.

Referring now to FIG. 4, the first plate 10 includes a first plate body15 that defines a first surface 18, a second surface 20 opposite thefirst surface 18, and an edge 22 that is connected between the firstsurface 18 and the second surface 20. The first plate 10 includes afirst holder 9 supported by the first plate body 15, a pulleyarrangement 13 supported by the first plate body 15, and a fixingarrangement such as a second holder 16, supported by the first platebody 15. The edge 22 defines an outer perimeter of the first plate 10,and the first plate defines a plate thickness T that extends from thefirst surface 18 to the second surface 20. The first plate 10 can definea substantially cuboid shape with a rectangular cross-section whosecorners are rounded to, for example, minimize soft tissue irritation.The first plate 10 can define a length as measured along its major axisas desired, such as approximately 20 mm. The first plate 10 can define awidth measured along its minor axis as desired, such as approximately 7mm. The thickness T as measured from the first surface 18 to the secondsurface 20 can be as desired, such as approximately 2 mm. However, asthe skilled person would of course understand other dimensions are ofcourse possible. For example, in treatment of a torn Syndesmosis joiningthe tibia to the fibula or a torn AC joint the length, width and depthcould be approximately 12 mm, approximately 5 mm and approximately 1.5mm, respectively.

The first holder 9 is configured to fixedly hold a fixed end 5 a of thesuture 7 in position and defines a starting point from which the suture7 is threaded around the pulley arrangement 13 to the second holder 16.In one embodiment, the first holder 9 can be configured as a channelthat extends between the first and second surfaces 18 and 20, anddefines respective apertures that extend into the first and secondsurfaces 18 and 20. Thus, the aperture can extend through the firstplate body 15 from the first surface 18 to the second surface 20. Theimplant assembly 1 can include a holding arrangement that includes thefirst holder 9 in combination with a holding element 5 c (see FIG. 2B)supported by the suture 7. For instance, the holding element 5 c can bedefined on or by the suture 7. The holding element 5 c could be astopper 5 c. As shown by FIG. 2C, the stopper 5 c could be an annulusformed around the fixed end 5 a having a diameter greater than thediameter of the channel of the first holder 9. That is, the stopper 5 c,which can be an annulus, is dimensioned so that it abuts the first orsecond surface 18 or 20, respectively, of the first plate 10 in a regionsurrounding the respective aperture of the first holder 9, therebypreventing the fixed end 5 a being pulled into the channel. The stoppercan be formed of any suitable material. As the skilled person wouldunderstand, the stopper can be a suitable resilient or plasticallydeformable material such as metals, for example, stainless steel, andpolymers.

Other holding mechanisms capable of holding the fixed end 5 a in a fixedposition relative to the first plate 10 are of course possible as theskilled person would understand. The holding element could be anotherstopper variant. For example, the holding element could be a plugarranged on the fixed end 5 a that is shaped to be pulled into thechannel and interfere with the wall of the channel to form aninterference fit to prevent the fixed end 5 a from being pulled throughthe channel and thereby prevent the fixed end 5 a moving relative to thefirst plate 10. The plug has an insertion end and a trailing end. Theplug is shaped to define a taper having its widest point at the trailingend such that when the insertion end is pulled into the channel the plugmay increasingly interfere and may have a truncated cone shape.Similarly to the stopper described above, the plug may be formed from aplastically deformable biocompatible material such that when the plug isdisposed in situ in the channel it tends to resist the compressiveforces applied to it by the channel and thereby maintain theinterference fit. In another example, the holding element could be astopper in the form of an element crimped onto the fixed end 5 a. Thecrimp is dimensioned to abut the first or second surface 18 or 20,respectively, of the first plate 10 in a region surrounding the openingthereby preventing the fixed end 5 a being pulled into the channel. Inyet another example, the holding element could be a stopper in the formof a knot, or series of knots, formed in the end of the suture 7 that isdestined to be the fixed end 5 a.

Referring to FIGS. 5A and 5B, in an alternative embodiment of the firstplate 10, the second holder 16 can include a set screw arrangement 100.The set screw arrangement 100 has a set screw 102 arranged to cause theholding of the suture 7 in position relative to the first plate 10. Theset screw arrangement 100 can include a locking element 104. The setscrew 102 is configured to interact with the locking element 104 totransition the locking element 104 to a closed configuration in whichthe locking element 104 is in a holding position in which it holds thesuture 7 in position relative to the first plate 10. For instance, whenin the holding position, the suture can be captured between the lockingelement 104 and the first plate body 15. With the set screw arrangement100 the free end 5 b of the suture 7 can be easily fixed in the firstplate 10. The fixing could be during, for example, manufacture, anoperation on a patient, etc. Thus, the second end 5 b of the joiningelement 5 can be adjustably fixable to a fixing arrangement provided onone of the first or second plates 10 and 30, such as the first boneplate 10 as illustrated. The fixing arrangement can define a fixingregion, for instance between the locking element and the first platebody 15, in which the second end 5 b of the contractible element 5 isfixable to the first plate, for instance by one or more of a cam-lock ofthe type described above including a set screw and/or a clamp, oralternatively a knot or a crimp.

The set screw 102 has a first end 106 and a second end 108. The firstplate 10 includes a set screw channel 110 that extends at least into,for instance through, the first plate body 15. In accordance with theillustrated embodiment, the set screw channel 110 can extend into thefirst surface 18 toward, for instance to, the second surface 20. The setscrew channel 110 can be threaded such that the set screw 102 isconfigured to be positioned, for instance threadedly inserted, into theset screw channel 110 defined in the first plate 10. In a first endregion adjacent the first end 106, the set screw 102 is tapered to apoint 107 at the first end 106. The second end 108 is threaded to engagewith a thread formed in the set screw channel 110. The threadedrelationship between the second end 108 and the set screw channel 110provides a resistance force, due to, for example, friction, whichminimizes the likelihood that the set screw 102 may inadvertently orunexpectedly move relative to the set screw channel 110. The set screw102 can define a cavity 112 that extends into the second end 108. Thecavity 112 can be configured as a drive socket that is shaped to receivea drive tool, for example, a screwdriver. In use, a user engages thetool with the cavity 112 and uses it to rotate the set screw 102 toalter the position of the set screw 102 relative to the set screwchannel 110, thereby driving the set screw 102 into and out of the setscrew channel 110 in opposed rotative directions.

The locking element 104 has a trailing end 114 and a leading end 116opposite the trailing end 114. The first plate 10 defines a lockingelement channel 118 that extends into the first plate body 15 along adirection that is perpendicular to the set screw channel 110. Thelocking element 104 is positioned in the locking element channel 118,such that the locking element channel 118 supports the locking element104 and is shaped to guide the locking element 104 to and from theholding position. The locking element 104 extends from the trailing end114 to the leading end 116 along the locking element channel 118. Thetrailing end 114 is located in the set screw channel 110 and the leadingend 116 is located in a suture holding channel 120 defined in the firstplate body 15. The trailing end 114 is configured to be engaged by theset screw 102 in order to move the locking element 104 relative to thelocking element channel 118. The movement of the locking element 104relative to the locking element channel 118 varies the amount of theleading end 116 located in the suture holding channel 120. The movementtransitions the locking element 104 from a non-holding position, inwhich suture 7 positioned in the suture holding channel 120 is looselyreceived in the suture holding channel 120, to the holding position inwhich the holding end 5 b of suture 7 positioned in the suture holdingchannel 120 is fixedly held relative to the first plate 10.

In the particular embodiment shown by FIGS. 5A and 5B, the leading end116 is shaped in order to prevent inadvertent damage to the suturepositioned and held in the suture holding channel 120. For example, theleading end 116 can be rounded. The trailing end 114 can be angledrelative to a plane that extends perpendicular to a central axis of thelocking element 104 that extends longitudinally from the leading end 116to the trailing end 14. As shown, the entire trailing end 114 is angledrelative to the plane. However, as the skilled person would of courseunderstand, only a portion of the trailing end 114 may be angled. Theangle of the trailing end 114 may be selected to correspond to the angleof the taper defined by the set screw 102 in the first end region. Thecorrespondence of the angles may be selected in order to ensure a smoothengagement of the tapered first end region of the set screw 102 with thetrailing end 114 and a smooth deployment of the locking element 114 tothe holding position. The trailing end 114 can thus cam along thetapered first end region of the set screw as the set screw is driven tomove relative to the set screw channel 110.

In the particular embodiment shown by FIGS. 5a and 5b , the set screwchannel 110 and the suture holding channel 120 run parallel with respectto each other through the first plate 10. The first plate body 15includes a wall 124 that separates and spaces apart the set screwchannel 110 from the suture holding channel 120. Each of the set screwchannel 110 and the suture holding channel 120 have openings into therespective channels formed on the first surface 18 and second surface20. The locking element channel 118 runs perpendicular with respect toboth the set screw channel 110 and the suture holding channel 120through the first plate 10. The locking element channel 118 has a firstportion defined by a first aperture 126 through the edge 22 into the setscrew channel 110, a second portion which passes through the set screwchannel 110 and a third portion defined by a second aperture 128 thatpasses through the wall 124 into the suture holding channel 120. Thefirst aperture 126 is provided so that during assembly of the firstplate 10, for example, during manufacture or in the operating room, thelocking element 104 can be positioned in the locking element channel 118through the set screw channel 110. With set screw 102 arranged in theset screw channel 110 and the locking element 104 arranged in thelocking element channel, the relationship of the channels 110, 118 and120 with respect to each other provides that movement of the set screw102 along the set screw channel 110 in a first direction causes thelocking element 104 to move along the locking element channel 118 towardthe suture holding channel in a second direction which is perpendicularto the first direction resulting in an increase in the amount of theleading end 116 that is located in the suture holding channel 120. Whena suture 7 is positioned in the suture holding channel 120, the amountof the leading end 116 is increased until the suture 7 is fixedly heldin the first plate 10.

In operation, the set screw arrangement 100 is initially in an openconfiguration as shown by FIG. 5a . In the open configuration the suture7 is inserted into the suture holding channel 120, and is capable ofmoving relative to the first plate 10 in the suture holding channel 120.A user then manipulates the set screw 102 to rotate in a firstdirection, which causes the set screw 102 to advance in the set screwchannel 110, thereby causing the tapered first end 106 to abut thetapered trailing end 114 and cause the tapered trailing end 114 to camalong the tapered first end 106. As the tapered trailing end 114 camsalong the tapered first end 106, the locking element 104 moves furtherinto the suture holding channel 120. The engagement could be effected bya user inserting a driving instrument into the cavity 112 and rotatingthe set screw 102 such that the threaded second end 108 engages with thethreaded portion of the set screw channel 110. The set screw 102 can bedriven into the set screw channel 110 until the locking element 104 ismoved to a closed configuration, whereby the suture 7 is captured in thesuture holding channel 120 between the leading end 112 of the lockingelement 106 and an inner surface of the first plate body 15 that atleast partially defines the suture holding channel 120. In this regard,the holding channel 120 can be referred to as an adjustment region inwhich the suture 7 is positionally adjustable relative to the firstplate 10 that carries the second holder 16. An example of the closedconfiguration is shown by FIG. 5b with the suture 7 removed forsimplicity.

Turning now to the pulley arrangement 13, FIGS. 1 and 4 show that thepulley arrangement 13 can define a plurality of pulleys 14 supported bythe plate body 15. In the exemplary embodiment shown by FIGS. 1 and 4,the first plate has two pulleys 14. Each pulley 14 can include a firstchannel 14 a that extends through the plate body 15 from the firstsurface 18 to the second surface 20, a second channel 14 c that extendsthrough the plate body 15 from the first surface 18 to the secondsurface 20, and a central axle 14 b that is disposed between the firstand second channels 14 a and 14 c. In one embodiment, the pulley 14 hasa width measured along to the minor axis of the first plate 10 of 3 mmand a length measure along the major axis of the first plate 10 of 5 mm.However, as the skilled person would of course understand differentlengths and widths are of course possible and may be different dependingon the treatment for which the first plate 10 is to be used. The firstchannel 14 a and second channel 14 c are channels passing through thefirst plate 10 with apertures on the first and second surfaces 18 and20. The axle 14 b spaces apart or separates the first channel 14 a fromthe second channel 14 c. The axle 14 b is shaped to provide a smoothtransition from the first channel 14 a to the second channel 14 c in thedirection of motion of the suture 7. The axle 14 b can be fixedlyattached to the plate body 15, such that the axle 14 b has no movingparts. The smooth transition is provided to minimize fraying orotherwise damaging of the suture 7 during the initial adjustment to setthe implant assembly 1 and during the self-contraction of the suture. Inthe preferred embodiment, the smooth transition is provided by the axle14 b having a curved surface in at least a region over which the suture7 moves, in use. The axle 14 b may be cylindrical and have a circularcross-section with respect to the direction of motion of the suture 7 tothereby provide the smooth transition over the axle 14 b.

FIG. 6A shows a first embodiment of the axle 14 b. The axle 14 b has across-sectional dimension D in the direction from the first surface 18to the second surface that can be the same as the plate thickness T. Thecross-sectional dimension D can be a diameter or alternatively shapedcross-sectional dimension. However, as the skilled person wouldunderstand other cross-sectional dimensions can be chosen. The plate 10shown in FIG. 4A is suitable for the treatment of the bone fracture ofthe sacrum. For such a treatment, the thickness T of the plate 10 issufficient to support compressive forces that are to be applied to theiliac crest to maintain a reduction of the fractured sacrum S duringbone healing. The plate thickness T identified as being suitable forsuch a treatment is 2 mm. In this regard, for this exemplary embodiment,the cross-sectional dimension of the axle 14 b is 2 mm. However, as theskilled person would understand other plate thicknesses T andcross-sectional dimension D are of course possible for other treatments,in particular, where larger or smaller compressive forces are to beused. The axles 14 b can be spaced along the major axis of the firstplate 10, and can be aligned with each other such that their centralaxes are coincident with each other. The plate body 15 can include adivider wall 21 that is disposed between the axles 14 b, such that a oneof the axles 14 b extends along a first direction from the divider wall21 along the direction of the major axis, and another of the axles 14 bextends along a second direction from the divider wall 21 along thedirection of the major axis.

It should be appreciated that the first plate 10 can be constructed inaccordance with any number of suitable embodiments. For instancereferring now to FIG. 6B, the axle 14 b′ of the plate 10′ constructed inaccordance with a second embodiment can define a cross-sectionaldimension D′ along a direction from the first surface 18 to the secondsurface 20 that is smaller than the plate thickness T. Thecross-sectional dimension D′ can, for instance, be a diameter. Thedifference between the cross D′ and thickness T may be chosen so thatthe crests of the curved outer surface defined by the axle 14 b′ that isdisposed closest to the first and second surfaces 18 and 20,respectively, spaced a distance X from the respective the first andsecond surfaces 18 and 20 of the first plate 10. The distance X can belarger than or equal to the cross-sectional dimension, such as adiameter, of the suture 7. The plate thickness T can be the same as theplate thickness described with reference to FIG. 4. That is the platethickness T can be 2 mm. In one embodiment, the suture 7 may have a 0.5mm cross-sectional dimension, for instance a diameter, and thecross-sectional dimension D′ is 1 mm or less. In this exemplaryembodiment, the center of the axle 14 b′ is located equidistant from thefirst and second surfaces 18 and 20, respectively. However, as theskilled person would understand the location of the center of the axle14 b′ could of course be varied, and spaced closer to one of the firstand second surfaces 18 and 20 than the other of the first and secondsurfaces 18 and 20. For example, should a cross-sectional dimension D′of 1.5 mm be desired, but the distance X of 0.5 mm be desired toaccommodate the suture 7, then the center of the axle 14 b′ could be0.75 mm from the second surface 20 and 1.25 mm from the first surface18,

The second holder 16 is configured to fixedly hold the free end 5 b inposition after an initial and desired compression has been set to holdthe bone portion or portions together. In contrast to the first holder9, the second holder 16 defines an end location through which the suture7 is attached after having been woven through the pulley arrangement 13of the first plate 10, which can define a first pulley arrangement, anda pulley arrangement 31 of the second plate 30 (see FIG. 7), which candefine a second pulley arrangement. In one embodiment, the second holder16 is a channel passing through the first plate body 15, from the firstsurface 18 to the second surface 20, and can define apertures on thefirst and second surfaces 18 and 20, respectively. The second surface20, which is opposed to the first surface 18 that is destined to be abone facing surface, and thus faces and can abut the lateral surface 12a of the first bone portion 12, has a bearing surface configured toreceive a holding element that is arranged on the suture after a desiredcompression is set between the first and second plates. The holdingelement could be a stopper such as the crimp, knot or knots describedabove. The holding element could be a clamp or cleat arranged to receivea fixedly hold the free end 5 b. Other holding elements capable ofholding the free end 5 b in a fixed position relative to second holder16 are of course possible as the skilled person would understand. In aparticular embodiment, the second holder 16 is the set screw arrangement100 described above with reference to FIGS. 3A and 3B.

Referring now to FIG. 7, the second plate 30 can be constructed asdescribed herein with respect to the first plate 10 with the exceptionthat the second plate 30 can be devoid of holders, such that the secondplate does not have a holder, i.e., neither a first holder 9 nor asecond holder 16. That is, the second plate 30 has a second plate body35 that defines a first surface 34, a second surface 36 opposite thefirst surface 34, and an edge 38 that is connected between the firstsurface 34 and the second surface 36. The second plate 30 includes apulley arrangement 31 supported by the second plate body 35. The edge 22defines an outer perimeter of the second plate 30, and the second plate30 defines a plate thickness T that extends from the first surface 34 tothe second surface 36. The second plate 30 can define a substantiallycuboid shape with a rectangular cross-section whose corners are roundedto, for example, minimize soft tissue irritation. The second plate 30can define a length as measured along its major axis as desired, such asapproximately 20 mm. The second plate 30 can define a width measuredalong its minor axis as desired, such as approximately 7 mm. Thethickness T as measured from the first surface 34 to the second surface36 can be as desired, such as approximately 2 mm. However, as theskilled person would of course understand other dimensions are of coursepossible. For example, in treatment of a torn Syndesmosis joining thetibia to the fibula or a torn AC joint the length, width and depth couldbe approximately 12 mm, approximately 5 mm and approximately 1.5 mm,respectively. As the skilled person would understand, the second plate30 may be adapted to comprise a holder of the type described withrespect to the first plate 10 if desired.

The pulley arrangement 31 of the second plate 30 can have any number ofpulleys 32 as desired, such as three pulleys 32. Each pulley 32 caninclude a first channel 32 a that extends through the plate body 35 fromthe first surface 34 to the second surface 36, a second channel 32 cthat extends through the plate body 35 from the first surface 34 to thesecond surface 36, and a central axle 32 b that is disposed between thefirst and second channels 32 a and 32 c. The pulleys 32 can beconstructed as described above with regard to the pulleys 14 of thefirst plate 10. The difference between the first plate 10 and the secondplate 30 being that the second plate 30 has an additional third pulley32. That is, when the first plate 10 has two pulleys 14, the secondplate has three pulleys 32. The relationship between the pulleyarrangement 13 of the first plate 10 and the pulley arrangement 31 ofthe second plate is that the pulley arrangement 31 has one more pulleythan the pulley arrangement 13. The axles 32 b can be spaced along themajor axis of the second plate 30, and can be aligned with each othersuch that their central axes are coincident with each other. The secondplate body 35 can include a divider wall 39 that is disposed betweenadjacent ones of the pulleys 32.

Referring again to FIG. 1, a suture looping arrangement is shown inaccordance with one embodiment. The fixed end 5 a of the suture 7 can befixed to the first plate 10 in the manner described above, and thesuture 7 is looped from the first plate 10, through the second plate 30and back to the first plate 10 relative to which it is to be held. Thesuture 7 can be again looped through the first plate 10, through thesecond plate 30, and back to the first plate 10. The suture 7 can belooped through the first plate 10 and through the second plate 30 andcan extend back to the first plate 10 successively as many times asdesired, depending for instance on the number of pulleys 14 and 32 ofthe first and second plates 10 and 30, respectively. In accordance withthe illustrated embodiment, the suture 7 is looped through the secondplate 30 three times, once around each pulley 32, and looped through thefirst plate 10 twice, once around each pulley 14. The suture 7 is loopedthrough the pulleys 14 of the first plate 10 between successive loopingsthrough the pulleys 32 of the second plate 30. Similarly, the suture islooped through the pulleys 32 of the second plate 30 between successiveloopings through the pulleys 14 of the first plate 10.

When the suture 7 is looped through each of the pulleys 32 of the secondplate 30, the suture 7 extends through one of the first and secondchannels 32 a and 32 c such as the first channel 32 a in accordance withthe illustrated embodiment, along a direction away from the first plate10, around the axle 32 b, and through the other of the first and secondchannels 32 a and 32 c, such as the second channel 32 c in accordancewith the illustrated embodiment, along a direction toward the firstplate 10. The second channel 32 c can be disposed superior with respectto the first channel 32 a as illustrated. Thus, the suture 7 can extendfrom the first plate 10 through an inferior one of the first and secondchannels 32 a and 32 c along a direction away from the first plate 10,can loop around the axle 32 b, and can extend through a superior one ofthe first and second channels 32 a and 32 c along a direction toward thefirst plate 10.

When the suture 7 is looped through each of the pulleys 14 of the firstplate 10, the suture 7 extends through one of the first and secondchannels 14 a and 14 c such as the first channel 14 a in accordance withthe illustrated embodiment, along a direction away from the second plate30, around the axle 14 b, and through the other of the first and secondchannels 14 a and 14 c, such as the second channel 14 c in accordancewith the illustrated embodiment, along a direction toward the firstplate 10. The second channel 14 c can be disposed inferior with respectto the first channel 14 a as illustrated. Thus, the suture 7 can extendfrom the second plate 30 through a superior one of the first and secondchannels 14 a and 14 c along a direction away from the second plate 30,can loop around the axle 14 b, and can extend through an inferior one ofthe first and second channels 14 a and 14 c along a direction toward thesecond plate 30.

For implantation, the suture 7 is fixedly held by the first holder 9,successively looped through the pulleys 32 and 14, and is adjustablyarranged relative to the second holder 16. The suture 7 is loopedthrough the pulleys 14 and 32 of the pulley arrangements 14 and 31,respectively. In the exemplary arrangement shown by FIG. 1, the suture 7is looped through the three pulleys of the pulley arrangement 31 and thetwo pulleys of the pulley arrangement 14. In the looping arrangement ofsuture 7 shown in FIG. 1, the suture 7 is looped through the pulleys 14of the pulley arrangement 13 in the same manner. For example, the suture7 is looped through each pulley in a clockwise direction. In thisexample, should the first plate 10 and second plate 30 be pulled apartor the suture 7 tensioned so that the suture 7 becomes taut, the partsof the suture running between the first and second plates 10 and 30,respectively, may be substantially parallel with respect to each other.As the skilled person would of course understand, the suture 7 may belooped clockwise, counter-clockwise, alternate between being loopedclockwise and counter/clockwise, etc., through the pulleys 14 and 32 toachieve different suture looping arrangements as desired.

It should be appreciated that the alternative second plates can beconstructed in accordance with any number of suitable alternativeembodiments, for instance as shown in FIGS. 8A to 8E. The alternativesecond plate or plates 130, 130′, 130″, and 130′″ can have many featuresin common with the second plate 30 with the exception that thealternative second plates can have alternative pulley arrangements. Thedimensions of the alternative second plates 130, 130′, 130″, and 130′″can be as described in relation to the first plate 10 and the secondplate 30. An embodiment of the alternative second plates 130, 130′,130″, or 130′″ can be interchangeably used or used instead of the secondplate 30, as the skilled person would of course understand.

One form of the pulley arrangement of a first embodiment of the secondplate 130 is shown in FIGS. 8A-B, where the pulley arrangement isprovided by a shaft 138 located in a frame 132 that is defined by thesecond plate body 135. The frame 132 defines an inner surface thatdefines an opening 137 that extends through the frame body 135 from thefirst surface 134 to the second surface 136. The shaft 138 can dividethe opening 137 into first and second regions. Similar to the pulleyarrangements 13 and 31, the first region defines a first channel 37 aand the second region defines a second channel 37 b, each configured toreceive and exit the suture 7 to and from the second plate 130. Inaccordance with the illustrated embodiment, the second channel 137 b isdisposed superior with respect to the first channel 137 a. However, inthe pulley arrangement of the first alternative embodiment of the secondplate 130, there are no separate pulleys. Rather, the shaft 138 isshaped to provide a smooth transition from the first channel 137 a tothe second channel 137 b in the direction of extension and motion of thesuture 7. As can be seen from FIG. 9A, the shaft 138 may be cylindricaland have a circular cross-section with respect to the direction ofextension and motion of the suture 7 to thereby provide the smoothtransition over the entirety of the shaft 138. Thus, the shaft 138 candefine an axle that the suture 7 is configured to loop around in themanner described above with respect to the pulley arrangement 31.Referring again to FIGS. 8A-E, the second plate 130, 130′, 130″, and130′″ can define first and second apertures 134 a and 134 b that extendinto inner surfaces of the frame and spaced from each other along thedirection of the major axis of the second plate body 135. The first andsecond apertures 134 a and 134 b can be shaped and dimensioned to holdand support the shaft 138 in the frame with an interference fit or anysuitable alternative attachment as desired.

FIGS. 8C to 8E show pulley arrangements of the second, third and fourthembodiments of the second plate 130. The pulley arrangement of thesecond embodiment of the plate 130′ can include one pulley 140 a mountedon to the shaft 138. The pulley arrangement of the third embodiment ofthe plate 130 can have first and second pulleys 140 a and 140 b,respectively. The pulley arrangement of the fourth embodiment of theplate 130 can have first, second, and third pulleys 140 a, 140 b and 140c, respectively. The pulleys 140 a, 140 b and 140 c are arranged on theshaft 138 and spaced from each other along the length of the shaft. Thepulleys 140 a, 140 b, 140 c can be moveable, for instance rotatable,about the shaft 138, and thus rotatable with respect to the second platebody 135. Alternatively, the pulleys 140 a, 140 b, and 140 c can berotatably fixed to the shaft 138, and the shaft 138 can be rotatablewith respect to the second plate body 135. Alternatively still, thepulleys 140 a, 140 b, and 140 c can be rotatable with respect to theshaft 138, and the shaft 138 can be rotatable with respect to the secondplate body 135. With respect to the pulley arrangement 13 and 31 and theone provided by the shaft 138, use of rotatable pulleys 140 a, 140 b and140 c may reduce the friction forces between the suture and the pulleyarrangement as the skilled person would understand.

The pulleys 140 a, 140 b, 140 c are supported by the shaft 138. In thesecond embodiment of the second plate 130′ the pulley arrangement hasone pulley 140 a supported by the shaft 138. In the third embodiment ofthe second plate 130″ two pulleys 140 a, 140 b are supported by theshaft 138. In the fourth embodiment of the second plate 130′″ threepulleys 140 a, 140 b, 140 c are supported by the shaft 138. The pulleys140 a, 140 b, and 140 c can be translatable along the length of theshaft 138, or can be translatably fixed to the shaft. As the skilledperson would of course understand, different frames and pulleyarrangements of the second plate 130 are of course possible. Forexample, in an alternate arrangement of the plate 130 with a pulleyarrangement having one pulley or two pulleys, the frame could be sizedsuch that, in the direction of the shaft, the opposed ends of the pulleyarrangement are flush with respective inner edges of the frame. Further,the second plates 130 can have as many pulleys as desired.

Referring to FIG. 9B, each of the pulleys 140 can define a pulley body141 having a first end 142 and a second end 144 opposite the first end.The cross-sectional dimension of the pulley body 141 can vary from thefirst end 142 to the second end 144. For instance, the pulley body 141can be substantially circular in cross-section relative to a first planeextending perpendicular to a central axis of the pulley 140, such thatthe cross-sectional dimension defines a diameter. The pulley body 141can define a channel 146 that extends into one or both of the first andsecond ends 142 and 144. The channel 146 is shaped and dimensioned toreceive an adjacent second or first end 144 or 142, respectively, of anadjacent pulley 140. That is, the diameter of the channel 146 isslightly larger than the diameter of the end that is to be received inthe channel 146. In a region adjacent the first end 142, the diametertransitions from a first lesser diameter to a second diameter greaterthan the first diameter along a direction from the first end 142 towardthe second end 144. The transition between the first and seconddiameters forms a shoulder 148, which is arranged to abut a second endof an adjacent pulley when a portion of the first end 142 is arranged ina channel of the second end of the adjacent pulley. The channel 146 canrun through an entirety of the pulley body 141 from the first end 142 tothe second end 144. The channel 146 has a channel axis which isconcentric with a central axis of the pulley 140. The channel 146 isshaped and dimensioned so that the pulley 140 is rotatable about theshaft 138 when positioned thereon. Relative to the first plane, theinner surface of pulley body 141 that defines the channel 146 has asubstantially cross-section dimensioned slightly larger than that of theshaft 138. For instance, inner surface of the pulley body 141 can besubstantially circular, and the cross-sectional dimension of the innersurface of the pulley body 141 can be a diameter. The shaft 138 can alsobe cylindrical, such that the cross-sectional dimension of the shaft 138can also be a diameter. The pulley body 141 can define a groove 150 thatextends radially inward from an external surface of the pulley body 141toward a central axis of the pulley 140 along which the pulley body iselongate, and about which the pulley 140 is rotatable. The groove can bedisposed in a mid-region between the regions adjacent the first andsecond ends 140 and 142, respectively. The groove 150 is configured toreceive the suture 7 as the suture 7 is looped around the pulley 140. Ina plane extending from and parallel to the direction of the centralaxis, the groove 150 has a smooth or arc-shaped surface. The Forinstance, the surface of the groove 150 can define a distance, such as adiameter, that is measured in a direction parallel to the central axisbetween opposed sides of the groove and is larger than the diameter ofthe suture 7. Accordingly, the suture 7 is not inadvertently pinched inthe groove 150, and undesired friction is not inadvertently introduced.

As the skilled person would of course understand, although the pulleyarrangement 140 has been described with reference to its use as part ofan embodiment of the second plate 130, the pulley arrangement 140 couldbe adapted for use with the pulley arrangement 13 of the first plate 10.

The plates 10, 30 and 130 and their respective elements can bemanufactured from any suitable material, for example, metals such astitanium or steel or polymers such as Polyetheretherkeytone (PEEK) orreinforced PEEK.

Referring now to FIGS. 10A to 10C, an instrument 50 includes a body 51and a chamber 53 that extends into the body 51 and is configured toretain the implant assembly 1. The instrument 50 is configured toimplant the implant assembly 1 into at least one bone or bones, andfurther includes a deployment element, such as a deployer 52, that ismoveable between a first position and a second position relative to thechamber 53, the deployer 52 configured to deploy the implant assembly 1during, for example, a surgical operation. The deployer 52 has animplant engaging member, such as a pusher 54 that is manipulable with ahandle 56. The pusher 54 is spaced apart from the handle 56 with respectto an instrument axis IA running centrally along the instrument 50 by aconnector 58. The connector 58 may be a rod that fixedly couples thehandle 56 to the pusher 54 such that manipulation of the handle 56 isapplied directly to the pusher 54. The deployer 52 has a first end 60and a second end 62. The pusher 54 is located adjacent the first end 60and the handle 56 is located adjacent the second end 62. Thus, when theimplant assembly 1 is housed in the chamber 53, movement of the deployer52 from the first position to the second position engages the pusher 54with the implant assembly 1 to move at least part of the implantassembly 1, for instance one of the first and second plates 10 and 30,respectively, out of the chamber 53 through an opening of the chamber 53at the first end 80.

The instrument body 51, and thus the instrument 50, can include a cover64 that is elongate with respect to the instrument axis IA from a firstend 80 of the body 51 to a second end 82 that is distal of the plate,which can be the first plate 10. The instrument 50 can include one ormore radio-opaque elements arranged about the perimeter of the first end80. As the skilled person would of course understand, the radio-opaqueelements allow the first end 80 to be visible in a commonly availableimaging system such C-Arm that provides X-ray images. Alternativearrangements, features or elements are of course possible to make thefirst end visible to other imaging systems.

The cover 64 is shaped and dimensioned to surround the pusher 54 andconnector 58. The cover 64 as shown by FIGS. 10A to 10C is substantiallytubular and can have a circular cross-section. However, as the skilledperson would of course understand other shape covers 62 are of coursepossible. The cover 64 also has an outer diameter that is the same orsubstantially the same as the drill bit used in a surgical operation,which is described below in greater detail. For example, the drill bitmay be 16.0 mm and the outer diameter of the cover 64 may be 15.5 mm to16.0 mm. In other examples, the drill bit may be 4.5 mm in diameter, forexample, when an AC joint is being treated or may be 3.5 mm in diameterwhen a Syndesmosis is being treated.

In an initial configuration, the cover 64 provides a housing for thepusher 54 and the connector 58 such that those elements are shieldedfrom, for example, bodily tissue such as bone, skin, muscles, etc.,during a positioning phase of a surgical operation, which is describedin more detail below. As shown by FIGS. 10A to 10C, in the initialconfiguration, the cover 64 also houses the implant assembly 1, whichfor simplicity is shown without the suture 7 that is connected betweenthe first plate 10 to the second plate 30 in the manner described above,substantially along the instrument axis IA as the skilled person wouldunderstand. The first plate 10 is located proximate to the handle 56 andthe second end 82. The second plate 30 is located proximate to thepusher 54 and the first end 80. Thus the first plate 10 is disposedupstream with respect to the second plate 30. Otherwise stated, thefirst plate 10 is disposed closer to the handle 56 and the second end 82than the second place 30. Similarly, the second plate 30 is disposedcloser to the handle pusher 54 and the first end 80 than the first plate10. The plates 10 and 30 are positioned such that their major axesextend substantially parallel to the instrument axis IA and their minoraxes extend substantially perpendicular to the instrument axis IA. Thesuture 7 can be connected between the first and second plates 10 and 30inside the instrument 50 in the manner described above. For instance,the fixed end 5 a can be attached to the first holder 9, and the suturecan be successively looped through the pulley arrangements 31 and 13.The free end 5 b is arranged such that it is accessible through thesecond end 82. The free end 5 b may be secured to the handle 56.

Referring to FIG. 10B, the pusher 54 will now be described in moredetail. The pusher 54 has a pusher body 66 shaped to deploy the firstand second plates 10 and 30, respectively, during a deployment phase ofa surgical operation, which will be described in more detail below.

The pusher body 66 defines a forward engagement surface 68, an opposedend surface 70 that is disposed upstream of the engagement surface 68, aforward upper surface 72, a rearward upper surface 74 that extendsupstream from the forward upper surface 72, and at least one peripheralsurface 76 that is connected between the surfaces 68 and 70, and isfurther connected between the opposed lateral ends of the upper surfaces72 and 74. For instance, the peripheral surface 76 can be partiallycylindrical in shape. The body 66 runs along the instrument axis IA froma leading end, defined by the engagement surface 68, to a trailing end,defined by the end surface 70. The leading end is the first end 60 ofthe deployer 52. The surface 68 is an engagement surface arranged forengagement, for instance abutment, with the second plate 30 during adeployment phase, which is described in more detail below. In theinitial configuration. The instrument 50 can define a distance along theinstrument axis IA between the first end 60 or surface 68 and the firstend 80 of the instrument 50 that is sufficient to allow the second plate30 to extend longitudinally along the instrument axis IA and within thecover 64. In an exemplary embodiment, the second plate 30 is 20 mm inlength and the distance between the first end 60 or surface 68 and thefirst end 80 is greater than 20 mm, for example, 25 mm to accommodatethe second plate 30 within the cover pre-deployment. The engagementsurface 68 can be a substantially planar surface that lies in a planeextending normal to the instrument axis IA. The trailing end can definea location at which the pusher 54 is coupled to the connector 58. Thetrailing end is defined by the surface 70. The surface 70 is aconnection surface to which connector 58 is coupled. The connectionsurface 70 is substantially planar and lies in a plane extendingtransverse to the instrument axis IA.

The engagement surface 68 and the connection surface 70 are spaced apartfrom each other along the insertion axis IA by the surfaces 72, 74 and76. The surfaces 72 and 74 can be substantially planar, and the surface76 can be a curved surface that arcs from a first end to a second enddefined by opposed edges of the planar surfaces 72 and 74, which extendfrom the leading end to the trailing end. The surface 72 can lie in aplane that is substantially parallel to the instrument axis IA. Thesurface 74 can lie in a plane which is angularly offset relative to theinstrument axis IA. The surface 72 extends from the leading end to anintersection point at which the surface 72 meets the surface 74. Fromthe intersection point, the surface 74 tapers towards the trailing end.In this regard, the body 66 is wedge-like. That is, the body 66resembles a wedge having a curved base defined by the curved peripheralsurface 76 and having its widest point at the leading end as defined bythe distance between the planar surface 72 and the nadir of the curvedperipheral surface 76 that transitions to its narrowest point at thetrailing end due to the tapering of the surface 74.

The pusher 54 is shaped and dimensioned to be slideably moveable withinan inner surface 78 of the cover 64 for deploying the first and secondplates 10 and 30, respectively. The channel 53 of the instrument body 51defines a gap G between the body 66 of the pusher 54 and the innersurface 78 of the cover 64. The gap G is sufficient to allow the suture7 to be attached to the first and second plates 10 and 30 and ensurethat interference of the pusher 54 with the suture 7 during thedeployment phase described below is minimized. The gap G is sufficientlywide along a lateral direction that is perpendicular to the instrumentaxis IA so as to provide clearance that allows the first plate 10 to beremoved from the instrument 50. The tapered surface 74 can provide aramp that guides the first plate 10 through the gap G.

The peripheral surface 76 is shaped to guide the pusher 54 within thecover 58 relative to the instrument axis IA when the pusher 54 is moved.The surface 76 is arced to correspond to the arced inner surface 78 ofthe cover 58. With the pusher 54 located in the cover 64, the peripheralsurface 76 can abut the inner surface 78 so as to guide the pusher 54 totranslate relative to the cover 64 in a downstream direction (i.e., awayfrom the second end 82) and upstream relative to the cover 64 in anupstream direction (i.e., toward the second end 82). The surface 74 istapered to form a ramp. During the deployment phase described below, theramp serves to urge the first plate 10 out of the cover 64.

A surgical method describing an operation in which an embodiment of theimplantation system of the present invention is used to locate animplant assembly 1 on the first portion 12 and a second portion 11 ofthe Ilium bone for holding fractured portions of a sacrum bone Stogether for bone healing purposes (see FIG. 2A) will now be described.As the skilled person would of course understand, the surgical methoddescribed is by way of example, and other surgical methods are of coursepossible and within the scope of the invention. The skilled person wouldof course understand also that whilst the steps are described withreference to a bone and bone healing, the steps can of course be adaptedto prepare any musculoskeletal tissue for treatment using the implantassembly 1. Examples of such treatment include: treatment of a tornligament of a syndesmosis, for example, the syndesmosis between thetibia and fibula, and treatment of a torn ligament of the AC joint ofthe shoulder.

An implanted position of the implant assembly 1 on the first and secondportions 12 and 11, respectively, of the Ilium can be seen in FIG. 2A.In the implanted position, a post-operative phase takes place duringwhich, for example, healing, in particular of the bone, such as thesacral bone S, should occur. Several phases of operation can occur toposition in the implant assembly 1 in the implanted position. An initialphase is a preparation phase during which holes are formed in the bonethrough which the implant assembly 1 may be positioned. In a positioningphase, the implant assembly 1 is located for deployment from within theinstrument 50. A deployment phase is undertaken to place the secondplate 30 on, for example, the second portion 11 of the right Ilium, andthe first plate 10 on the first portion 12 of the left Ilium. With thefirst and second plates 10 and 30 in position, a setting phase iscommenced during which an initial compression is set by manipulation ofthe free end 5 b and the second holder 16. In this arrangement, theimplant assembly 1 applies a compression to the first and second Iliumcrests 12 and 11 for the purpose of maintaining compression across thesacrum S, resulting in a reduction of a fracture of the sacrum S andsupporting bone healing of the Sacrum S The post operative phase thencommences during which the self contracting suture 7 maintains thecompressive force on the first and second plates 10 and 30, whichconsequentially apply a compressive pressure to the right and left Iliumin order to continue to hold fractured portions of the sacrum togetherunder compression in support of bone healing.

The surgical method for treating a fractured sacrum will now bedescribed in more detail.

Preparation Phase

During the preparation phase of the surgical operation, themusculoskeletal tissue is prepared for receiving the implant assembly 1.During part of the preparation phase, the fracture of the sacrum S isreduced with, for example, reduction forceps or any suitable alternativestructure. After reduction of the fracture, Kirschner wires are placedacross the sacroiliac joint for stabilization. A borehole is drilled inthe first portion 12 of the left ilium, and another borehole is thendrilled in the second portion 11 of the right ilium. These boreholes inthe left and right ilium can interchanged according to preference, asthe skilled person would understand. The boreholes may be drilled withthe same drill bit in a single drilling step, for instance if the firstand second plates 10 and 30 are similarly dimensioned, or in separatedrilling steps, which can be with different drill bits if the first andsecond plates 10 and 30 are dimensioned differently from each other. Thedrill bit is removed leaving the bone reduced and prepared. The drillbit may be 16.0 mm in diameter. As the skilled person would of courseunderstand, the size of the drill bit may larger or smaller than 16.0 mmand may be of a size selected as the size appropriate for a surgicaloperation. For example, the drill bit may be 4.5 mm in diameter, forexample, when an AC joint is being treated and may be 3.5 mm in diameterwhen a Syndesmosis is being treated. The drill bit and resultingborehole can be of a dimension that is greater than the width of thefirst and second bone plates 10 and 30 along their minor axis, and lessthan the length of the first and second bone plates 10 and 30 alongtheir major axis.

Positioning Phase

During the positioning phase, the surgeon inserts the instrument 50containing the implant assembly 1 into the boreholes. As describedabove, the instrument 50 can include cutting flutes configured to formthe boreholes in the bone. Once the boreholes have been formed, thesurgeon can insert the cover 64, containing an implant assembly 1 firstthrough one of the boreholes that extend through one of the first andsecond bone portions 12 and 11, respectively, and then through the otherof the boreholes that extend through the other of the first and secondbone portions 12 and 11. For instance, in accordance with theillustrated embodiment, the cover 64 is inserted first through theborehole of the first bone portion 12, and then through the borehole ofthe second bone portion 11. As described above, the diameter of thecover 64 can be substantially the same as the diameter of the drill bitto ensure that the cover 64 fits snugly in the boreholes. With theinstrument 50, in particular, the cover 64, spanning from the boreholeof the first, right bone portion 12 to the borehole of the second, leftbone portion 11, an image can be taken of the sacrum S and iliac crestsusing any suitable imaging system. For instance, a C-Arm or othersuitable imaging device can obtain and display an image that identifiesthe location of the instrument 50 relative to the boreholes. Theinstrument 50 may be repositioned as needed. As described above, theinstrument 50 has one or more radio-opaque elements disposed at thefirst end 80. The C-Arm provides an image, for example, an X-ray image,that a surgeon can use ensure a desired position of the instrument 50relative to the boreholes. For example, the image can show that thefirst end 80 is positioned in the one of the borehole, for example ofthe second bone portion 11 at the left ilium, such that subsequentdeployment of the second plate 30 of the implant assembly 1 out thecover 64, and thus out the instrument 50, will cause the second plate 30to be disposed adjacent the lateral surface 11 a of the second boneportion 11, and further subsequent deployment of the first plate 10 outthe cover 64, and thus out the instrument 50, will cause the first plate10 to be disposed adjacent the lateral surface 12 a of the first boneportion 12. For instance, the first end 80 can be positionedsubstantially flush with the lateral surface 11 a of the second boneportion 11. Thus, the instrument 50 can include an external surface thatis shaped and dimensioned to be passed through the boreholes. Inaccordance with one embodiment, the external surface can includedrilling flutes for making boreholes in a bone, such as in the first andsecond bone portions 12 and 11.

Deployment Phase

With the instrument 50 appropriately aligned, the implant assembly 1 maybe deployed. In a first step, the plate 30 is pushed out of the cover 64using the deployer 52. To move the deployer 52 from the first positionto the second position the handle 56 is manipulated by translating thehandle 56 relative to the instrument axis IA. The handle 56 istranslatable in the downstream direction from a first or initialconfiguration whereby the pusher 54 does not exert a deployment forceonto either the first or second plates 10 and 30 that would cause theplate to be ejected from the instrument, to a deployed configurationwhereby the pusher 54 exerts a deployment force onto either or both ofthe first and second plates 10 and 30 sufficient to eject the plate outthe instrument 50. Thus, as the handle 56 is translated downstream, thepusher 54 is transitioned from the initial configuration to the deployedconfiguration, such that the first end 60 or engagement surface 68 ofthe pusher 54 is translated downstream along the instrument axis IA froma first distance away from the end 80 of the instrument 50 along theinstrument axis IA to a second shorter distance from the end 80 alongthe instrument axis IA. The pusher 54, for instance at the engagementsurface 68, engages, directly or indirectly, the second plate 30 duringmovement form the initial to the deployed configuration. The downstreammovement of the pusher 54 causes the engagement surface to force, forinstance push, the second plate 30 out of the cover 64 to a firstdeployment site, which can be the lateral surface 11 a of the secondbone portion 11.

In the deployed configuration, the surface 68 can be substantially flushwith the end 80 of the instrument 50. The imaging device, for example aC-Arm, is then used to check that the second plate 30 has been deployedon the expected lateral side 11 a of the left ilium bone portion 11, forinstance such that the first surface 34 of the second plate body 35 ispositioned facing the lateral side 11 a. In accordance with oneembodiment, the first surface 34 can abut the lateral side 11 a, or canbe spaced from the lateral side 11 a so that the first surface 34 ispositioned to abut the lateral side 34 when the first and second plates10 and 30 are drawn toward each other after deployment.

With the deployer 54 in the deployed configuration, the surgeon can thendraw the first end 80 of the instrument 50 from the borehole of thesecond bone portion 11 to the borehole of the first bone portion 12. Inso doing, the suture 7, whose fixed end 5 a has been pre-fastened to thefirst plate 10, and which has been pre-looped around the pulleyarrangements 13 and 31, is pulled from the instrument 50 through the gapG into a location between the first and second bone portions 12 and 11.The instrument 50 is then removed from the borehole of the first boneportion 12 so that the first end 80 is disposed adjacent the lateralsurface 12 a of the first bone portion 12, such that the suture 7extends through the borehole of the first bone portion 12. An image canagain be taken of the instrument 50 to ensure that the first end 80 ispositioned as desired. The handle 56 can then be retracted along theinstrument axis IA, until the first implant 10 rides along the taperedupper surface 54 through the gap G to a position downstream of theengagement surface 68. Because the second plate 30 is tethered to thefirst plate via the suture 7, movement of the instrument away from thesecond plate 30 can draw the first plate 10 into the cover 64.Subsequent movement of the handle 56 downstream toward the first end 80causes the handle to move to the deployed configuration whereby thepusher 54 exerts a deployment force onto the first plate 10 sufficientto eject the first plate 10 out the instrument 50, for instance out theopening 80, to a second deployment site, which is preferably differentto the first deployment site. For instance, the second deployment sitecan be located at the lateral surface 12 a of the first bone portion 12.

The surgeon then checks with the imaging device to ensure that the firstplate 10 is in the expected position, with the first surface 18positioned facing the lateral side 12 a. In accordance with oneembodiment, the first surface 18 can abut the lateral side 12 a, or canbe spaced from the lateral side 12 a so that the first surface 18 ispositioned to abut the lateral side 18 when the first and second plates10 and 30 are drawn toward each other after deployment.

Setting Phase

With first and second plates 10 and 30 in the desired position such thatthe first surfaces 18 and 34 face the respective lateral surfaces 12 aand 11 a, the surgeon grips the free end 5 b of the suture 7 that islooped between the first and second plates 10 and 30, either manually orvia any suitable tensioning instrument, and sets a desired tension. Inthe event that the free end 5 b of the suture 7 is attached to thehandle 56, the surgeon can retract the handle 56 upstream along theinstrument axis IA, or can manually translate the instrument 50 awayfrom the second surface 20 of the first plate. The free end 5 b is thuspulled through the second holder 16, while the locking element 104 is inthe open configuration, thereby allowing the suture 7 to translatethrough the first plate 10, for instance through the suture holdingchannel 120 (see FIG. 5A). As the suture 7 translates through the firstplate 10, the suture becomes tensioned along its length, including atthe regions of the suture 7 that are looped around the first plate 10,the regions of the suture 7 that are looped around the second plate 30,and the regions of the suture 7 that extend between the first and secondplates 10 and 30, respectively. Once a desired tension is reached in thesuture 7 with the first surfaces 18 and 34 abutting the respectivelateral surfaces 12 a and 11 a, respectively, or other suitable outerbone surfaces, the free end 5 b is secured to the second holder 16. Forinstance, the locking element 104 can be moved to the closedconfiguration, thereby capturing the suture 7 in the first plate 10, forinstance in the manner described with respect to FIG. 5B). It should beappreciated that while the first and second holders 9 and 16 are bothincluded in the first plate 10, one of the first and second holders 9and 16 can alternatively be included in the first plate 10 while theother of the first and second holders 16 can be included in the secondplate 30. For instance, the first plate 10 can include the first holder9, while the second plate 30 can include the second holder 16. Thus, thefirst fixed end 5 a of the contractible element 5 has a can be fixed toone of the first and second plates 10 and 30, and the second free end 5b of the contractible element 5 can be adjustably fixable to a fixingarrangement provided on one of the first or second plates 10 and 30.

The desired tension thereby sets an initial compression that the firstand second plates 10 and 30 apply to their respective parts of the bone,for example, the right and left ilium bone parts 12 and 11,respectively, to support bone healing. The desired tension may beidentified by feel and experience. Alternatively a tension measuringdevice, such as a spring scale, may be attached to the suture 7 to reacha numerically desirable tension level. When the suture 7 has reached thedesired tension level, the implant assembly 1 can be further imaged toensure that the implant assembly 1 has been implanted as desired, (e.g.,ensuring that plates 10 and 30 are positioned as desired, and thefracture of the sacrum S is reduced as desired, and that the suture 7 ispositioned as desired). Adjustments to the implant assembly 1 can thenbe made as desired, and then the surgical procedure can be completed.The method steps can be repeated to implant a second one of the implantassemblies 1 as illustrated in FIG. 3, or any number of the implantassemblies 1 as desired.

Post Operative Phase

During the post operative phase, the self-contracting element 5 isoperates to maintain the compression. As described above, this isachieved through an osmotic process in which the core of the element 5expands thereby contracting the outer sheath surrounding the core withthe net effect that the distance between the fixed end 5 a and the freeend 5 b along the length of the element 5 is reduced. The reduction inthe length of the element 5 counteracts any unwanted or undesired creepor stretching that may occur during bone healing, for instance as theilium portions 12 and 11 move relative to the first and second plates 10and 30, respectively, for instance toward each other. In so doing, theinitial compression is substantially maintained. For instance, in somecases, the increase in compression of the element 5 can greater than themigration of the ilium portions 12 and 11 relative to the first andsecond plates 10 and 30, such that the compression in the element 5 maybe increased during the post operative phase. In other cases, theincrease in compression of the element 5 is less than the migration ofthe ilium portions 12 and 11 relative to the first and second plates 10and 30, such that the compression in the element 5 may be decreasedduring the post-operative phase. In either case, the element 5 incombination with the plates 10, 30 can cooperate to ensure that asatisfactory compression is maintained at the fracture location of thesacrum S to support bone healing.

If desired, the first plate 10 and second plate 30 and the element 5 maybe removed once the treatment has finished and the fracture has healedto a desired degree. This may be done through a first incision on theleft side of the ilium and a second incision of the right side of theilium. The suture 7 can be severed as desired to allow the first andsecond plates 10 and 30, respectively, to be withdrawn through therespective incisions.

The above description has described how embodiments of the implantassembly 1 may be used to support bone healing of a fractured sacrum Sin accordance with certain embodiments. However, as the skilled personwould of course understand, the implantation system having an implant orplurality of implant assemblies 1 and an instrument or instruments 50could be used to support bone healing, ligament healing, tendon healing.In other surgical operations a torn AC-CC joint or a torn syndesmosis ofthe tibulafibula joint may be treated.

It will of course be understood that this description is by way ofexample only; alterations and modifications may be made to the describedembodiment without departing from the scope of the invention as definedin the claims.

The invention claimed is:
 1. An implant assembly comprising: a suture; afirst implant member having a thickness and including: a first channelthat extends through the thickness of the first implant member along afirst channel axis, wherein the first channel fixedly receives thesuture; a second channel that extends through the thickness of the firstimplant member along a second channel axis, the second channelconfigured to adjustably hold the suture, wherein the first and secondchannels are spaced from each other and circumferentially closed to eachother in their respective entireties with respect to a direction thatintersects both the first and second channel axes; and a locking elementtranslatable between a holding position configured to hold the suture inthe second channel, and a non-holding position configured to release thesuture such that the suture is translatable in the second channel; and apulley arrangement disposed between the first and second channels, thepulley arrangement including: a plurality of openings that 1) extendthrough the thickness of the first implant member and 2) are elongatealong a first direction perpendicular to the thickness of the firstimplant member; and a plurality of axles that extend through respectiveones of the openings along a direction perpendicular to both the firstdirection and the thickness of the first implant member, the axlesdividing the openings into first channels and second channels, and asecond implant member configured to be positioned opposite the firstimplant member, wherein the suture is woven about each of the axles andextends through each of the first and second channels of each of theplurality of openings so as to attach to the second implant member. 2.The implant assembly of claim 1, further comprising a linear lockingelement channel that is open to the second channel, wherein the lockingelement is linearly translatable between the holding position and thenon-holding position in the locking element channel.
 3. The implantassembly of claim 2, further comprising a third channel configured toreceive a set screw that is configured to urge the locking element fromthe non-holding position to the holding position.
 4. The implantassembly of claim 3, wherein the third channel runs parallel to thesecond channel, and the locking element channels runs transverse to boththe second and third channels.
 5. The implant assembly of claim 1,wherein the axles are cylindrical.
 6. The implant assembly of claim 5,wherein the first implant member has one more axle than the secondimplant member.
 7. The implant assembly of claim 1, the second implantmember further comprising: a second pulley arrangement including: aplurality of second openings that 1) extend through a thickness of thesecond implant member and 2) are elongate along a respective firstdirection perpendicular to the thickness of the second implant member;and a plurality of second axles that extend through respective ones ofthe second openings along a direction perpendicular to both therespective first direction and the thickness of the second implantmember, the second axles dividing the second openings into respectivefirst channels and respective second channels, and wherein the suture iswoven about each of the axles of the first and second implant membersand through the first and second channels of each of the plurality ofopenings of each of the first and second implant members so as to securethe first and second implant members to each other.
 8. An implant systemcomprising: the implant assembly of claim 7; and an instrumentincluding: a chamber that houses the implant assembly, and an externalsurface shaped and dimensioned to be passed through boreholes formed ina bone; and a deployer disposed between the first and second implantmembers in the chamber, the deployer having a forward engagement surfaceand a rearwardly extending tapered surface, wherein the deployer is 1)movable in a forward direction to thereby cause the engagement surfaceto push the second implant member out of the chamber, 2) subsequentlyretractable in a rearward direction in the chamber so as to cause thefirst implant member to ride along the tapered surface to a positionforward of the engagement surface in the chamber, and 3) subsequentlymovable in the forward direction to thereby cause the engagement surfaceto push the first implant member out of the chamber.
 9. An implantsystem comprising: the implant assembly of claim 1; and an instrumentincluding: a chamber that houses the implant assembly, and an externalsurface shaped and dimensioned to be passed through boreholes formed ina bone; and a deployer disposed between the first and second implantmembers in the chamber, the deployer having a forward engagement surfaceand a rearwardly extending tapered surface, wherein the deployer is 1)movable in a forward direction to thereby cause the engagement surfaceto push the second implant member out of the chamber, 2) subsequentlyretractable in a rearward direction in the chamber so as to cause thefirst implant member to ride along the tapered surface to a positionforward of the engagement surface, and 3) subsequently movable in theforward direction to thereby cause the engagement surface to push thefirst implant member out of the chamber.